A timber harvester feeder device according to the preamble is known from the applicant's previous publications WO 85/05589 and WO 99/25526. A timber harvester usually has two feed tracks jointed oppositely to each other, stripping blades, and a cutting device. The frame of the feed track is installed on articulated arms. The roller chain is fitted around a drive sprocket, driving the middle row of links, and a turnover member, generally a pair of idler wheels. The dimensions of the roller chain are adapted to the dimension of the toothing of the drive sprocket, which has limited the diameter of the rollers.
A track feed has obvious advantages over drive rollers. The first publication deals with a situation, in which rolling bases and roller chains are used. This substantially improves the durability of the track feed, as the solution allows the loading to be transferred directly to the sliding base, thus avoiding loading peaks in the track. The latter publication discloses a curved rolling base, so that the track-feed device imitates a large drive roller, the length of the grip with the timber being much longer than in any real drive roller, the diameter of which remains much smaller for practical reasons. Due to the curved rolling base, the mechanism is simplified, as one joint of the feed device can be eliminated. A crawler track is a special roller chain, in which the rollers and pins wear in use. In order to reduce friction, the rollers are equipped with bushings. Correspondingly, the rolling bases wear in use and, like the crawler track, are preferably made to be replaceable. In known rolling bases, grooves must be machined between the rollers, to prevent the links from coming in contact with the base.